DE202021103675U1 - Magnetic check valve - Google Patents

Abstract

Magnetic check valve (100) with a valve body (1) and a valve housing arrangement (2), wherein the valve body (1) is guided in the valve housing arrangement (2) in an axially displaceable manner and the fluid channel (3) of the valve housing arrangement (2 ) closes, with the axial holding force being generated by a repelling magnet arrangement, with a concentric piston (7) connected to the valve body (1) via the end face having a first magnet arrangement (4) and the valve body guide (6) having a second magnet arrangement (5) characterized in that the first magnet arrangement (4) is arranged in a cavity of the piston (7) and is surrounded on all sides in a media-tight manner and the second magnet arrangement is arranged in a cavity in the valve body guide (6) and is surrounded on all sides in a media-tight manner.

Description

TECHNICAL FIELD

The present invention relates generally to a magnetic check valve, particularly for use in a sterile environment.

TECHNICAL BACKGROUND

Check valves are designed to allow fluid flow in only one direction. If the pressure in the other direction is greater than the closing force, the fluid opens the valve. Designs are generally known in which a valve body closes the fluid channel counter to the flow direction, with the closing force of the valve body being applied via a helical spring. One variant is the substitution of the spring with a repelling magnet arrangement, which reduces contamination in the valve arrangement.

The field of application for check valves is very diverse. In process technology and in particular in sterile technology, it is necessary that no deposits can form in the valve due to cavities, gaps or sealing rings. Friction of the individual components can also lead to abrasion. Such contamination should be avoided as far as possible in the largely sterile manufacture of pharmaceutical products or foods, for example.

In the area of bathroom fittings are off CN 101871539B Magnetic check valves are already known, in which a first magnet is located on the valve body and a second magnet on the valve body guide, with the two ring-shaped exposed magnets repelling one another, as a result of which the valve body blocks the fluid channel against the direction of flow. The valve seals against the fluid via an exposed radial sealing ring on the valve body.

JPH03213777A also discloses a magnetic non-return valve for sanitary installations, in which two repelling magnets press a valve body in a sealing manner against a fluid channel. The guide pin of the valve body dips into a blind hole in the valve body guide and thus forms a cavity with it. The magnets are arranged in such a way that the respective end faces repel each other. Identical to CN 101871539B the valve body seals via an exposed sealing ring located on the valve body.

Known magnetic check valves with repelling polarity have so far mainly been found in the sanitary sector. These valves are disadvantageous in an aseptic environment because the exposed magnet assembly and sealing rings create inaccessible cavities in which residues of cleaning agents or product residue can accumulate. Cleaning and sterilization is often carried out using the CIP and SIP processes at temperatures of up to 140 °C, which means that common magnet types (type N) lose their magnetic effect. Abrasion is also promoted if the valve body is not supported in the valve guide housing.

It is therefore the object to provide a magnetic check valve with a repelling magnet arrangement for use in an aseptic environment, in which the above disadvantages are at least partially eliminated.

SUMMARY

The present invention solves this problem. According to a first aspect, the present invention provides a magnetic check valve with a valve body and a valve housing arrangement, the valve body being guided in an axially displaceable manner in the valve housing arrangement and closing the fluid channel of the valve housing arrangement by a holding force counteracting the direction of flow, the axial holding force being caused by a repelling magnet arrangement is produced, wherein a concentric piston connected to the valve body via the end face comprises a first magnet arrangement and the valve body guide comprises a second magnet arrangement, wherein the first magnet arrangement is arranged in a cavity of the piston and is surrounded on all sides in a media-tight manner and the second magnet arrangement is in a cavity of the Valve body guide is arranged and is surrounded on all sides media-tight.

Further aspects and features of the present invention result from the dependent claims, the accompanying drawings and the following description of embodiments.

• 1 eine Schnittansicht eines Ausführungsbeispiels eines erfindungsgemäßen magnetischen Rückschlagventils;
• 2 eine erste Ausführungsform einer schematischen Magnetanordnung;
• 2A eine zweite Ausführungsform der Magnetanordnung.
• 3 eine erste Ausführungsform einer zweiten Magnetanordnung
• 3A eine zweite Ausführungsform der zweiten Magnetanordnung
• 4 eine erste Ausführungsform der allseitigen Umhüllung einer ersten Magnetanordnung durch einen Kolben
• 4A eine zweite Ausführungsform der allseitigen Umhüllung der ersten Magnetanordnung durch den Kolben
• 4B eine dritte Ausführungsform der allseitigen Umhüllung der ersten Magnetanordnung durch den Kolben
• 4C eine vierte Ausführungsform der allseitigen Umhüllung der ersten Magnetanordnung durch den Kolben

Embodiments of the invention will now be described by way of example and with reference to the accompanying figures. It shows:

• 1 a sectional view of an embodiment of a magnetic check valve according to the invention;
• 2 a first embodiment of a schematic magnet arrangement;
• 2A a second embodiment of the magnet arrangement.
• 3 a first embodiment of a second magnet arrangement
• 3A a second embodiment of the second magnet arrangement
• 4 a first embodiment of the all-round encasing of a first magnet arrangement by a piston
• 4A a second embodiment of the all-round encasing of the first magnet arrangement by the piston
• 4B a third embodiment of the all-round encasing of the first magnet arrangement by the piston
• 4C a fourth embodiment of the all-round encasing of the first magnet arrangement by the piston

DESCRIPTION OF THE EMBODIMENTS

1 shows a magnetic check valve according to the invention. A detailed description is preceded by general explanations of the embodiments.

There are embodiments in which a first magnet arrangement comprises a rod-shaped magnet arrangement through which the central axis passes. The magnet arrangement comprises at least one magnet. The rod-shaped magnet can have a round cross-sectional geometry. The polarity of the magnet arrangement is divided transversely to the axis of rotation. The locking force of the valve is set via the strength of the magnetic field. The magnet is selected according to the required holding force before assembly. The first magnet arrangement is aligned along the axis of rotation of the valve in accordance with an even distribution of force.

There are embodiments in which the second magnet arrangement comprises an annular magnet arrangement which is aligned concentrically with the piston. In this case, the magnet arrangement comprises at least one magnet which is aligned concentrically to the first magnet arrangement. The second magnet arrangement can comprise an annular, one-piece magnet or a plurality of bar magnets with the same polarity, which are arranged radially around the axis of rotation, the polarity of the magnet arrangement being divided transversely to the axis of rotation.

There are embodiments in which the first magnet arrangement partially penetrates the second magnet arrangement. The polarity of the first and second magnet configurations is such that the end faces of the first and second magnet configurations repel each other. Due to the combination of bar magnet and ring magnet, an additional radial force is generated due to the closed magnetic field lines in addition to the axial force. Since the second magnet arrangement is mounted in a fixed manner and the first magnet arrangement is mounted in an axially displaceable manner, the first magnet arrangement is mounted radially, which additionally minimizes the friction of the valve body, as a result of which abrasion is reduced.

There are embodiments in which the first magnet arrangement is enclosed by the hollow space of the piston in a materially bonded manner. Due to the complete encapsulation, no residues or deposits should form on the piston. For a clean valve run, it is advantageous if the outer geometry of the piston is as free as possible of notches or bumps. After inserting the magnet arrangement, the multi-part piston housing can be closed by TIG, MIG/MAG or laser welding. In this case, a low heat input into the magnet arrangement is advantageous since magnets lose their magnetic properties if the thermal load is too high. Laser welding is characterized by a high welding speed and low thermal input, which means that the magnetization is retained.

There are embodiments in which the second magnet arrangement is enclosed by the cavity of the valve body guide in a materially bonded manner. In order to minimize unevenness and to maintain the magnetic properties, the components of the valve body guide are preferably connected by means of laser welding, with the second magnet arrangement being introduced into the cavity of the valve body guide provided for this purpose before joining. The geometry of the valve body guide is ring-shaped so that no cavities form as far as possible.

There are embodiments in which at least the valve body guide is made of stainless steel. To avoid corrosion, stainless austenitic steel is preferred. The material 1.4435 is resistant to all forms of corrosion and can therefore be used in a sterile production environment such as medical technology, the pharmaceutical industry or food processing.

There are embodiments in which the piston includes a shoulder to limit the immersion depth of the valve body. In the event of overstressing, the first magnet arrangement can "dip" too far into the second magnet arrangement. As a result, the magnetic field acting in the longitudinal direction counter to the fluid flow can be reversed, as a result of which the valve remains permanently open. To avoid this effect are located on the piston Shoulders that can be designed as a twisted heel.

There are embodiments in which the first magnet arrangement and/or the second magnet arrangement comprises high-temperature-resistant magnets. For sterilization, the non-return valves are autoclaved at temperatures of up to 140 °C. Widespread type N magnets such as N52 neodymium magnets (NdFeB) permanently lose magnetization at a temperature of 65 °C, which changes the preset holding force of the valves and makes the check valve unusable. Therefore, high-temperature magnets with a service temperature of at least 140 °C (e.g. type SH, UH, EH, AH, Y) are used.

There are embodiments in which the closing force of the valve body is adjusted via the magnet strength. In order not to influence the magnetic field, if possible all components of the check valve should be made of a non-magnetic material, apart from the magnet arrangements. The individual components are preferably made of an identical material in order to avoid contact corrosion. The magnet arrangements are preferably designed as permanent magnets. By selecting the magnet before assembly, the holding force of the valve body can be preset according to customer requirements.

There are embodiments in which the valve body guide is connected via a cage located within the valve body assembly. Corresponding to reduced maintenance effort and easier cleaning, the cage can be connected to the valve guide housing in a non-positive or positive manner.

There are embodiments in which the valve housing arrangement can be divided radially and is connected in a sealing manner via at least one radial sealing ring. The mutually facing end faces of the valve housing arrangement have a circumferential groove corresponding to the cross section of the radial sealing ring. The radial sealing ring can be designed as an O-ring, flat or profile sealing ring. Depending on the requirement profile, the sealing ring can be made of the materials EPDM, silicone, FEP silicone, FKM, FFKM or as a PTFE-based composite material (Gylon®, Tuf-Steel®).

There are embodiments in which the valve housing arrangement is divided into two, which comprises a valve body housing and a valve guide housing, with the connection taking place in a non-positive manner via a union screw connection. As a result, the non-return valve can be installed without special tools or dismantled into its individual parts for cleaning or maintenance. The valve body housing or the valve guide housing includes an external thread in the cylindrical area of the facing faces. The housing part without an external thread has a shoulder on the outside, with both housing halves being screwed together using a union nut.

There are embodiments in which the valve seat surface of the valve body is made of PTFE. Depending on the requirements, the valve body can be designed as a membrane or as a ball variant. In the ball variant, the valve body can have a partial PTFE coating in the area of the valve seat or be made entirely of PTFE, which avoids gaps in which residues can form.

1 shows a sectional view of a magnetic check valve 100 with a valve body 1, which is concentrically connected to a piston 7 via the end face. The piston 7 is axially displaceable, positioned concentrically in a valve body guide 6 along the longitudinal direction of the valve and penetrates the valve body guide 6 completely. The piston 7 comprises a rod-shaped first magnet arrangement 4 in a cavity provided for this purpose, the first magnet arrangement being surrounded on all sides by the piston 7 . The valve body guide 6 is statically connected to the valve guide housing 2b in a non-positive and/or positive manner via a cage 9. The valve body guide 6 includes a cavity in which an annular second magnet assembly 5 is surrounded on all sides. The polarity of the first and second magnet arrangement 4, 5 is arranged oppositely, as a result of which the valve seat surface 12 of the valve body 1 is pressed counter to the flow direction 14 in the conically tapering area of the valve body housing 2a. As a result, the fluid channel 3 remains closed counter to the direction of flow 14 until a pressure of the fluid can overcome the restoring force of the repelling magnet arrangement 4, 5. The immersion depth of the valve body 1 is limited by a shoulder 8 in the form of a shoulder on the piston 7. The valve body housing 2a is coupled to the valve guide housing 2b via a union nut 11 . A radial sealing ring 10 is inserted between the contact surfaces of the valve body housing 2a and the valve guide housing 2b, with both housing halves 2a, 2b having a circumferential groove which together form a cross section for receiving the radial sealing ring 10.

2 and 2A show schematic representations of the first and second magnet arrangement 4, 5 in the installed state to one another. The first and second magnet assemblies are magnetized axially through the magnet elevation axis. 2 shows a first embodiment in which the opposite the force acting in the direction of flow 14 via the south pole S1 of the first magnet arrangement 4 and S2 of the second magnet arrangement 5 is caused.

2A shows a second embodiment of the orientation of the magnet arrangements 4, 5, wherein the acting force is caused via the north pole N1 of the first magnet arrangement 4 and N2 of the second magnet arrangement 5.

3 and 3A show embodiments of the second magnet arrangement, with a first embodiment in 3 comprises an annular one-piece magnet assembly.

3A shows a second embodiment of the second magnet arrangement 5, wherein several bar magnets 5A are arranged radially around the axis of rotation. The longitudinal axes of all bar magnets 5A are arranged parallel to the axis of rotation, with the bar magnets 5A being magnetized axially through the magnet height axis.

4 , 4A , 4B and 4C show schematic representations of four embodiments for the all-round encasing of the first magnet arrangement 4 by the piston 7. The embodiments differ in the cohesively joined individual parts of the piston. In 4 the housing of the piston 7 is divided radially in the area of the first magnet arrangement 4 . As a result of this arrangement, both housing parts of the piston 7 are automatically aligned concentrically via the first magnet arrangement 4, with the two housing parts of the piston 7 being connected to one another via a weld seam S.

4A shows a second embodiment in which the piston 7 is divided radially in the area of the end face of the magnet arrangement 4 and forms a common plane, the separating plane of the two housing parts of the piston 7 having a step. As a result, both housing parts of the piston 7 can be aligned with one another and the heat input into the magnet arrangement 4 when the weld seam S is produced is reduced.

4B 1 shows a third embodiment in which the end face of the piston 7 facing away from the valve body has a blind hole for inserting the magnet arrangement 4, the hole being closed with a radial weld seam S via a cylindrical or conical closure on the end face.

4C 1 shows a fourth embodiment, in which the end face of the piston 7 facing the valve body 1 has a blind hole for inserting the magnet arrangement 4, the hole being sealed with a radial weld seam S by means of a cylindrical sealing piece on the end face. This arrangement means that the weld seam S is as far away from the magnet arrangement 4 as possible, as a result of which the heat input is further reduced. In addition, the weld seam S is covered by the valve body 1 in this arrangement.

Other embodiments and variations of the present invention will be apparent to those skilled in the art.

reference list

1

valve body

2

valve body assembly

2a

valve body housing

2 B

valve guide housing

3

fluid channel

4

First magnet arrangement

5

Second magnet arrangement

5a

bar magnets

6

valve body guide

7

Pistons

8th

shoulder

9

Cage

10

radial sealing ring

11

Union screw connection

12

valve seat surface

14

flow direction

100

check valve

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• CN 101871539B [0004, 0005]

Claims (14)

Magnetic check valve (100) with a valve body (1) and a valve housing arrangement (2), wherein the valve body (1) is guided in the valve housing arrangement (2) in an axially displaceable manner and the fluid channel (3) of the valve housing arrangement (2 ) closes, with the axial holding force being generated by a repelling magnet arrangement, with a concentric piston (7) connected to the valve body (1) via the end face having a first magnet arrangement (4) and the valve body guide (6) having a second magnet arrangement (5) comprises, characterized in that the first magnet arrangement (4) is arranged in a cavity of the piston (7) and is surrounded on all sides in a media-tight manner and the second magnet arrangement is arranged in a cavity in the valve body guide (6) and is surrounded on all sides in a media-tight manner. Check valve (100) after claim 1 , wherein the first magnet arrangement (4) comprises a rod-shaped magnet arrangement (4a) through which the central axis passes. Check valve (100) according to one of Claims 1 or 2 , wherein the second magnet arrangement (5) comprises an annular magnet arrangement (5a) which is aligned concentrically with the piston (7). Check valve (100) according to any one of the preceding claims, wherein the first magnet arrangement (4) partially penetrates the second magnet arrangement (5). Check valve (100) according to one of the preceding claims, wherein the first magnet arrangement (4) is enclosed by the hollow space of the piston (7) in a materially bonded manner. Check valve (100) according to one of the preceding claims, wherein the second magnet arrangement (5) is enclosed by the hollow space of the valve body guide (6) in a materially bonded manner. Check valve (100) according to one of the preceding claims, wherein at least the valve body guide (6) is made of stainless steel. Check valve (100) according to one of the preceding claims, wherein the piston (7) comprises a shoulder (8) for limiting the immersion depth of the valve body (1). Check valve (100) according to one of the preceding claims, wherein at least the first magnet arrangement (4) and/or the second magnet arrangement (5) comprises high-temperature-resistant magnets. Check valve (100) according to any one of the preceding claims, wherein the closing force of the valve body (1) is adjusted via the magnet strength. Check valve (100) according to any one of the preceding claims, wherein the valve body guide (6) is connected via a cage (9) located within the valve housing assembly (2). Check valve (100) according to one of the preceding claims, in which the valve housing arrangement (2) can be divided radially and is connected in a sealing manner via a radial sealing ring (10). Check valve (100) according to one of the preceding claims, wherein the valve housing arrangement (2) is divided into two, which comprises a valve body housing (2a) and a valve guide housing (2b), the connection being non-positive via a union screw connection (11). Check valve (100), characterized in that at least the valve seat surface (12) of the valve body (1) is made of PTFE.

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